1. Field of the Invention
The present general inventive concept relates to an inkjet printhead, and more particularly, to an inkjet printhead including a heat generating resistor made of a titanium nitride compound TiN0.3.
2. Description of the Related Art
Ink ejection mechanisms used in inkjet printers are largely categorized into two different types: an electro-thermal transducer type (bubble-jet type) in which a heat source is employed to form bubbles in ink causing the ink to be ejected, and an electro-mechanical transducer type in which ink is ejected as a result of a change in volume due to deformation of a piezoelectric element.
In the electro-thermal transducer, heat is delivered to the ink that contacts a heater, and the temperature of the ink, which is a water-based fluid, increases rapidly above a boiling point. When the temperature of the ink increases above the boiling point, ink bubbles are generated in the ink and the ink bubbles increase pressure of the ink. The pressurized ink is ejected through a nozzle due to a pressure difference between the atmospheric pressure and the pressure of the ink. The ink is ejected onto a surface of a printing paper, in the form of ink droplets, which minimize a surface energy of the ejected ink. This process may be controlled by a computer and is known as a Drop-on-Demand method.
However, such electro-thermal transducers have a durability problem due to the repeated thermal shocks caused by heating the ink and the pressure of the ink bubbles occurring in the heated ink, and it is difficult to control the size of the ejected ink droplets and to increase the printing speed.
Recently, due to demand of high speed and high accumulation printing, an arrayhead and a linehead including a printhead corresponding to the width of a printing paper have been developed.
For inkjet printers having such an arrayhead or a linehead, a highly efficient heat source is required to reduce a driving power thereof. To increase the efficiency of the heat source, it is desirable to eliminate a heat source protection layer, which is disposed on the heat source between the heater and the ink and is provided for electrical insulation. The heat source protection layer itself has a low thermal conductivity and thus becomes an obstacle when trying to reduce the driving power.
A heat source that is not protected by the heat source protection layer and contacts the ink directly should satisfy the following two conditions. First, as the heat source directly contacts the ink and operates at a high temperature, the heat source may easily corrode. Therefore, the heat source should be made of a strong corrosion-resistant material. Second, because the heat source should directly handle cavitation, which occurs when bubbles are formed and then collapse, the heat source needs to be resistant to a cavitation force.